Linear thruster with compliant head

Abstract

A linear thruster (10) comprises a thruster assembly (15) and a compliant head assembly (100). Thruster assembly (15) includes a housing (20), a pair of guide rods (30) supported by bearings (29) in housing (20), a thrust plate (40) attached below housing (20) to guide rods 30, a power unit, such as pneumatic cylinder (50), and a thrust rod (60). Compliant head assembly (100) includes a translation block (120), a set of first leaf springs (140) supporting translation block (120) above thrust plate (40) such that translation block (120) can move forward and rearward, a compliant head (160), and a set of second leaf springs (180) supporting compliant head (160) from translation block (120) at a position below thrust plate (40) such that compliant head (160) can move left and right due to resiliency of second leaf springs (180) and forward and rearward with movement of translation block (120).

I claim: 
     
       1. A linear thruster comprising: a thrust rod movable in a thrust direction defining a thrust axis from a retracted position to an extended position;   a thrust plate connected to said thrust rod and moveable therewith;   a translation block;   a first leaf spring connecting, in the direction of the thrust axis and opposite said thrust direction, said translation block to said thrust plate such that said translation block has a movement axis due to resiliency of said first leaf spring, orthogonal to the thrust axis;   a compliant head;   a second leaf spring connecting, in the thrust direction, said compliant head to said translation block such that said compliant head can move orthogonal in all directions to the thrust axis.   
     
     
       2. The linear thruster of claim 1 wherein: said compliant head can move, due to resiliency of said second leaf spring, orthogonal to the thrust direction and orthogonal to the movement axis of said translation block and can move parallel to the movement axis of said translation block.   
     
     
       3. A linear thruster comprising: a thrust rod movable in a thrust direction defining a thrust axis from a retracted position to an extended position;   a thrust plate connected to said thrust rod and moveable therewith;   a translation block;   a plurality of spaced, parallel first leaf springs connecting, in the direction of the thrust axis and opposite said thrust direction, said translation block to said thrust plate such that said translation block has a movement axis, due to resiliency of said first leaf springs, orthogonal to the thrust axis;   a compliant head;   a plurality of spaced, parallel second leaf springs connecting, in the thrust direction, said compliant head to said translation block such that said compliant head can move orthogonal in all directions to the thrust axis.   
     
     
       4. The linear thruster of claim 3 wherein: said compliant head can move, due to resiliency said second leaf springs, orthogonal to the thrust direction and orthogonal to the movement axis of said translation block and can move parallel to the movement axis of said translation block.   
     
     
       5. A linear thruster comprising: a housing;   a plurality of spaced, parallel guide rods supported by said housing in vertical sliding axial movement with respect to said housing;   a thrust plate attached below said housing to said guide rods and moveable therewith in a thrust direction defining a thrust axis from a retracted position to an extended position; said thrust plate including: a front side; and   a rear side;     a thrust rod attached to said thrust plate for moving said thrust plate;   a power unit attached to said housing and operatively connected to said thrust rod for moving said thrust rod;   a translation block including: a front side;   a rear side;   a left side; and   a right side;     a pair of parallel, spaced first leaf springs comprising: a front leaf spring connecting said thrust plate front side with said translation block front side; and   a rear leaf spring connecting said thrust plate rear side with said translation block rear side; said first leaf springs supporting said translation block above said thrust plate such that said translation block can move forward and rearward due to resiliency of said first leaf springs;     a compliant head including: a left side; and   a right side;     a pair of parallel, spaced second leaf springs comprising: a left leaf spring connecting said translation block left side with said compliant head left side; and   a right leaf spring connecting said translation block right side with said compliant head right side; said second leaf springs supporting said compliant head from said translation block at a position below said thrust plate such that said compliant head can move left and right due to resiliency of said second leaf springs and forward and rearward with movement of said translation block.     
     
     
       6. The linear thruster of claim 5 wherein: a said guide rod includes a rod extension extending downward from said thrust plate; and   said compliant head includes a bore receiving said rod extension; said bore and said rod extension cooperating to allow a pre-determined amount of forward-backward and left-right movement of said translation block relative to said thrust plate.   
     
     
       7. The linear thruster of claim 5 further including: retracted restriction means cooperating in the retracted position between said housing and said compliant head for restricting forward-backward and left-right movement of said compliant head in the retracted position.   
     
     
       8. The linear thruster of claim 7 wherein: said retracted restriction means comprises: a rigid pin attached to said housing or said compliant head and cooperating in the retracted position with a pin bore; and   a pin bore in the other of said housing or said compliant head adapted to receive said pin and to allow a pre-determined amount of forward-backward and left-right movement of said pin therein.     
     
     
       9. The linear thruster of claim 5 further including: extended restriction means cooperating in the extended position between said housing and said compliant head for restricting forward-backward and left-right movement of said compliant head in the extended position.   
     
     
       10. The linear thruster of claim 9 wherein: said extended restriction means comprises: a shaft attached to said housing and cooperating in the retracted position with a shaft bore; and   a sleeve attached to said compliant head, adapted to receive said shaft and to restrict the amount of forward-backward and left-right movement of said shaft therein.     
     
     
       11. The linear thruster of claim 5 wherein: said translation block includes: openings receiving said guide rods.     
     
     
       12. The linear thruster of claim 11 wherein: said guide rod openings are adapted to prevent left-right movement of said translation block relative to said guide rods and to allow a pre-determined amount of forward-backward movement of said translation block relative to said guide rods.   
     
     
       13. The linear thruster of claim 12 wherein: a said guide rod includes a rod extension extending downward from said thrust plate; and   said compliant head includes a bore receiving said rod extension; said bore and rod extension cooperating to allow a pre-determined amount of forward-backward and left-right movement of said translation block relative to said thrust plate.   
     
     
       14. The linear thruster of claim 12 further including: crash protection means operating between said thrust plate and said compliant head for allowing a pre-determined amount of forward-backward and left-right movement of said compliant head relative to said thrust plate.   
     
     
       15. The linear thruster of claim 14 wherein: said crash protection means comprises: a crash bolt protruding from said thrust plate or said compliant head; and   a crash bore in the other of said thrust plate or said compliant head cooperating with said crash bolt and adapted to allow a pre-determined amount of forward-backward and left-right movement of said crash bolt therein.     
     
     
       16. A linear thruster comprising: a housing;   a plurality of spaced, parallel guide rods supported by said housing in vertical sliding axial movement with respect to said housing;   a thrust plate attached below said housing to said guide rods and moveable therewith from a retracted position to an extended position defining a thrust axis; said thrust plate including: a front side; and   a rear side;     a thrust rod attached to said thrust plate for moving said thrust plate;   a power unit attached to said housing and operatively connected to said thrust rod for moving said thrust rod;   a translation block including: a front side;   a rear side;   a left side; and   a right side;     a pair of parallel, spaced first leaf springs comprising: a front leaf spring connecting said thrust plate front side with said translation block front side; and   a rear leaf spring connecting said thrust plate rear side with said translation block rear side; said first leaf springs supporting said translation block above said housing such that said translation block can move forward and rearward due to resiliency of said first leaf springs;     a compliant head including: a left side; and   a right side;     a pair of parallel, spaced second leaf springs comprising: a left leaf spring connecting said translation block left side with said compliant head left side; and   a right leaf spring connecting said translation block right side with said compliant head right side; said second leaf springs supporting said compliant head from said translation block at a position below said thrust plate such that said compliant head can move left and right due to resiliency of said second leaf springs and forward and rearward with movement of said translation block.     
     
     
       17. The linear thruster of claim 16 further including: stroke adjustment means operating between said translation block and said housing for adjustably controlling the minimum distance of said translation block to said housing.   
     
     
       18. The linear thruster of claim 16 wherein: said translation block includes: a vertical bore therethrough; and further including:     set screw means in said translation block vertical bore and adjustably protruding below said translation block for contacting said housing for adjustably controlling the minimum distance of said translation block to said housing.   
     
     
       19. The linear thruster of claim 16 wherein: a said guide rod includes a rod extension extending downward from said thrust plate; and   said compliant head includes a bore receiving said rod extension; said bore and said rod extension cooperating to allow a pre-determined amount of forward-backward and left-right movement of said translation block relative to said thrust plate.   
     
     
       20. The linear thruster of claim 16 wherein: said translation block includes: openings receiving said guide rods.     
     
     
       21. The linear thruster of claim 20 wherein: said guide rod openings are adapted to prevent left-right movement of said translation block relative to said guide rods and to allow a pre-determined amount of forward-backward movement of said translation block relative to said guide rods.   
     
     
       22. The linear thruster of claim 16 wherein: a said guide rod includes a rod extension extending downward from said thrust plate; and   said compliant head includes a bore receiving said rod extension; said bore and said rod extension cooperating to allow a pre-determined amount of forward-backward and left-right movement of said translation block relative to said thrust plate.   
     
     
       23. The linear thruster of claim 16 further including: crash protection means operating between said thrust plate and said compliant head for allowing a pre-determined amount of forward-backward and left-right movement of said compliant head relative to said thrust plate.   
     
     
       24. The linear thruster of claim 23 wherein: said crash protection means comprises: a crash bolt protruding from said thrust plate or said compliant head; and   a crash bore in the other said thrust plate or said compliant head and cooperating with said crash bolt.     
     
     
       25. The linear thruster of claim 16 further including: retracted restriction means cooperating in the retracted position between said housing and said compliant head for restricting forward-backward and left-right movement of said compliant head in the retracted position.   
     
     
       26. The linear thruster of claim 25 wherein: said retracted restriction means comprises: a rigid pin attached to said housing or said compliant head and cooperating in the retracted position with a pin bore; and   a pin bore in the other said housing or said compliant head adapted to receive said pin and to allow a pre-determined amount of forward-backward and left-right movement of said pin therein.     
     
     
       27. The linear thruster of claim 16 further including: translation block restriction means cooperating in the retracted position between said housing and said translation block for restricting forward-backward movement of said translation block in the retracted position.   
     
     
       28. The linear thruster of claim 27 wherein: said translation block restriction means comprises: a post attached to said housing or said translation block and cooperating in the retracted position with a post bore; and   a post bore in the other said housing or said compliant head adapted to receive said shaft and to allow a pre-determined amount of forward-backward movement of said shaft therein.     
     
     
       29. The linear thruster of claim 16 further including: extended restriction means cooperating in the extended position between said housing and said compliant head for restricting forward-backward and left-right movement of said compliant head in the extended position.   
     
     
       30. The linear thruster of claim 29 wherein: said extended restriction means comprises: a shaft attached to said housing and cooperating in the retracted position with a shaft bore; and   a shaft bore attached to said compliant head, adapted to receive said pin and to restrict the amount of forward-backward and left-right movement of said shaft therein.     
     
     
       31. A linear thruster comprising: a housing;   a plurality of spaced, parallel guide rods supported by said housing in vertical sliding axial movement with respect to said housing;   a thrust plate attached below said housing to said guide rods and moveable therewith in a thrust direction defining a thrust axis from a retracted position to an extended position; said thrust plate including: a front side; and   a rear side;     a thrust rod attached to said thrust plate for moving said thrust plate;   a power unit attached to said housing and operatively connected to said thrust rod for moving said thrust rod;   a translation block including: a front side;   a rear side;   a left side;   a right side; and   openings receiving said guide rods; said guide rod openings adapted to prevent left-right movement of said translation block relative to said guide rods and to allow a pre-determined amount of forward-backward movement of said translation block relative to said guide rods;     a constant length spring connected to said thrust plate and to said translation block and supporting said translation block above said thrust plate such that said translation block can move forward and rearward, but not substantially up and down, due to resiliency of said constant length spring;   a compliant head including: a left side; and   a right side;     a leaf spring connected to said translation block and to said compliant head right side and supporting said compliant head from said translation block at a position below said thrust plate such that said compliant head can move left and right due to resiliency of said leaf spring and forward and rearward with movement of said translation block.